In most conventional buildings, both residential and commercial, electrical receptacles are spaced out on walls at fixed intervals. This allows for convenient distribution of power, but does not typically provide any additional functionality. Each receptacle typically provides two outlets. The style of the provided outlet is usually determined by geographical location and the electrical standards of region.
In many buildings, emergency lighting is required to provide a means for navigating in the dark. There are two common needs for navigation in the dark. The first is a conventional night light situation, whereby a light is required to provide illumination in a dark environment on a regular basis; the other is for backup lighting. Backup lighting is also referred to as blackout lighting, and is required when there is a lower failure and lighting cannot be turned on.
The prior art has attempted to address this situation by developing a number of solutions including both nightlights and rechargeable lights. Nightlights are typically plugged-in to one of the outlets provided in a standard receptacle. They often include switches, that can be either photosensitive or manually controlled. This allows the nightlight to be deactivated during daylight when it is not needed. Rechargeable lights are also designed to be connected to an outlet. Many of these lights will activate when they are no longer in a charging state. Thus, a rechargeable flashlight of this design will activate both upon being unplugged and upon a power failure.
One problem with both of these designs is that they consume an electrical outlet, and require external components that can be removed and accidentally disconnected. Thus, an integrated solution provides advantages.
Backup lighting is necessary to ensure that individuals can safely navigate through dark and even unfamiliar locations. The need for these lights to operate on emergency power is increased in locations such as hospitals, nursing homes, and both industrial and commercial buildings in which individuals may be unfamiliar with floor plans and layouts. Residential homes benefit from emergency lighting as it enables homeowners, residents, and guests to safely navigate the home when power outages occur. Emergency rescue personnel are often hampered by the lack of knowledge of floor designs, increasing the time and effort required to rescue people from potentially dangerous situations.
Many solutions to backup lighting involve a dedicated lighting unit connected to the electrical power main. When a loss of power is detected, these systems turn on. Although they provide blackout lighting, they require additional wiring, which is inconvenient during construction, and expensive as a retrofit. The external units are often unsightly and are single purpose infrastructure items that serve no function other than emergency lighting.
A key limitation of conventional emergency lighting, especially considering residential utilization, is installation of bulky and generally unappealing systems that require direct access to electrical outlet. In addition, these conventional emergency lights have a single operational function and hence cannot be tailored different emergency lighting scenerios (ie power loss, low-light illumination, smoke/fire detection). In addition, alternate lighting can be provided by external devices (ie a night light plugged into a receptacle) however, these tend to be bulky and diminish the use of the wall receptacle for other purposes.
Thus, there remains a need for discrete emergency lighting that can automatically illuminate and can allow a user enough flexibility to select the appropriate emergency illumination situation.
Prior art attempts at addressing this need are discussed below. Typically they do not provide a sufficiently integrated and flexible system.
U.S. Pat. Nos. 6,010,288 and 6,000,807 both describes a light switch plate and wall receptacle plate that are installed in place of the normal flush mounted plastic cover plates. While generally easy to install as this senses the absence of power wirelessly, this type of fixture plate (in both thickness and length) is bulky, potentially unappealing and only has the power outage lighting feature via LED lights. Similarly U.S. Pat. No. 5,473,517 also use this same type of bulky light switch plate but utilizes direct connection to 120 VAC to sense the presence or absence of power to both with the illumination source being a relatively inefficient fluorescent tube arrangement.
U.S. Pat. No. 6,045,232 describe an emergency light arrangement that has both the capability of providing lighting for power out conditions and night light for illumination during low light levels. While this does have expanded utility as it provides more than just one type of emergency lighting and does not utilize bulky plates, this is a direct replacement of the wall receptacle removing the ability to use this as a normal outlet. This then precludes the use of this in certain locations where there are limited numbers of wall receptacles.
U.S. Pat. No. 6,805,469 describes the complete replacement of the internal wall receptacle and light switch units with a custom light switch and wall receptacle that internally contain the electronics and batteries for an emergency light. Both arrangements use illumination (light switch via the toggle, wall receptacle via the face of the receptacle body) during power out conditions and conform to the size and shape of normal light and wall receptacles, thus maintaining the normal appearance. However, both have only one possible function and importantly, when the batteries require replacement or the device has failed and requires replacement, the user must disassembly the unit from the electrical box creating a potential safety hazard for the user.
Thus there remains a need for an emergency lighting system that conforms to the normal configuration these standard wall receptacles, contain a level of flexibility to allow the user to select the desired functions, maintain the full use and capability of the substituted wall receptacle, and is easy and safe for the user. In addition, as technology changes and advances, there also is a need to ensure that the state-of-the-art can be utilized with minimal user cost or change to the installed system.